深水J-Lay大直径薄壁管道的理论分析及数值模拟

Theoretical Analysis and Numerical Simulation of Large-Diameter and Thin-Wall Pipelines During Ultra-Deep J-Lay Installation

建立了考虑Brazier效应的管道非线性微分方程,利用奇异摄动理论得到了J-Lay管道形态的解析解,应用迭代法求出管道的弯矩、轴力等关键参数,同时采用有限元法对管道理论解的正确性进行了验证,研究了张紧力、水深以及水流力对J-Lay管道形态和弯矩的影响.理论结果表明:J-Lay管道铺设过程中,其弯矩的峰值总是出现在触底点(TDP)附近的管段,在一定的范围内增加张紧力,管道的形态越平缓、弯矩峰值越小,对铺管越有利;其他参数不变、增加水深时,管道弯矩峰值并不是单调地增加;水流力与铺管方向相反时会增加管道的弯矩峰值,对铺管不利.

In this paper,a nonl inear dif ferent ial equat ion of pipel ines is establ ished by considering the BRAZIE1R effect. Then, the analytical solution to the J-Lay pipeline configuration is obtained through the singular perturbation theory, and such key parameters as the bending moment and the axial force of the pipeline are solved by means ofthe iterative method. Meanwhile,the analytical solution of the pipeline is proved to be correct by means of the finiteelement method. Finally,the influences of the tension,the water depth and the ocean and bending moment of the J-Lay pipeline are investigated. Theoretical results show that （1） in the laying process of the JLay pipeline,the pak of the bnding moment is always present in the pipeline sction near the touch down point; （2） when the tension is increased in a certain range, th e more smooth th e p ip e l in e co nfig uration i s, the smaller the pak value of the bnding moment will be,which is beneficial to the pipeline laying; （ 3 ） when th e othe r parameters are constant and the water depth increases, th e in c re a se of th e b e n d inpipeline is not monotonous ; an d （ 4 ） when th e cu r re n t force is in th e opp osite d ire c t io n of th e p ip e la y in g ,th e b e n -ding moment peak value of the pipeline increases,which is detrimental to the pipeline laying.